Add CHANGELOG.md to describe 'notable' changes

After listening to "The Changelog" podcast about change logs, I decided
that it would be good to start doing this for this project, as there
might actually be the possibility that someday someone else will use
fanci in their project.
Merge pull request #3 from liip/keep-a-changelog

Add CHANGELOG.md to describe 'notable' changes
Add extract test for arrays
Implementation of rename functionality